From navigation and file management to permissions, processes, networking, package management, and shell scripting for working confidently in any terminal.
The command line is a text-based interface for interacting with your computer. Instead of clicking icons, you type commands — and the shell interprets them and passes them to the Operating System. What is a Shell? A shell is a program that: Almost all Linux distributions come with a shell called bash. Shell Full Name…
Linux organizes files in a hierarchical directory structure — a tree pattern starting from the root directory (/). Understanding how to navigate this tree is one of the most fundamental skills in the command line. Introduction Command Description cd / Move to the root directory ls Show files and folders in the current directory ls…
Three essential commands for exploring and viewing files: ls (list directory contents), file (identify file types), and less (view file contents page by page). The ls Command List the contents of a directory with detailed information about files. Command Description ls /var List contents of /var ls /var ~ List both /var and your home…
Links are special types of files that point to other files or directories. Linux has two kinds: symbolic links (soft links) and hard links. Understanding the difference is essential for working with the Linux filesystem. Symbolic Links (Soft Links) A symbolic link (also called a soft link) is a special file that acts as a…
Wildcards are special characters that allow us to select filenames based on character patterns. They’re also called glob patterns — and they’re one of the most powerful features of the command line. A Quick Look at the Examples Pattern Matches *.txt Any file with .txt extension ?a?.txt 3-char name, second char a, .txt [abc]* Starts…
These are the core file management commands in Linux. They let you create, copy, move, rename, and delete files and directories from the command line. Make and Delete Directories Command Description mkdir d1 Create a single directory named d1 mkdir d2 d3 Create multiple directories at once mkdir -p d4/d5/d6 Create nested directories (creates parents…
What are commands? When you type a command in the shell, several things can happen behind the scenes. The type and which commands help you identify what kind of command you’re running and where it lives on the system. Overview Command Description ls /usr/bin List all executable files in /usr/bin type cd Show what kind…
These three tools help you learn how to use commands — from quick built-in help to full documentation manuals. Knowing how to use them is essential for becoming self-sufficient on the command line. Overview Tool Purpose Best For help Help for bash builtins Built-in commands like cd, echo –help Quick help for external commands Most…
These three commands help you discover and explore commands on your system. They’re complementary tools for finding the right command and learning more about it. Overview Command Purpose Best For whatis One-line description of a command Quick lookup when you know the name apropos Search by keyword Finding a command when you don’t know its…
Aliases let you create custom shortcuts for commands — long commands, frequent combinations, or anything you type often. They save time and reduce typos. Overview Command Description alias Show all existing aliases alias lmh=’cd ~/cli; ls’ Create a temporary alias nano ~/.bashrc Edit shell config file source ~/.bashrc Apply changes unalias lmh Remove an alias…